210 MEMOIRS ON THE COLEOPTERA 



and toward the sides, the punctures bearing stiff erect hairs, the 

 apex wholly smooth to feebly punctulate. 



Pseudaphonus n. gen. 



In this genus the general form of the body is somewhat as in 

 Ligyrus, though in most species more pyriform, but it differs in the 

 still smaller head, in which the transverse reflexed apical ridge is 

 almost at the extreme apex, less removed therefrom than in 

 Aphonus or Orizabus and is never bilobed; the clypeal apex in 

 front of the carina bears a very dense porrect fringe of pale setae. 

 The mentum is nearly flat, rather narrow, gradually obtusely 

 acuminate, moderately punctate and setose throughout. The 

 mandibles must be very minute, as I am unable to perceive the 

 slightest vestige of them in any of my examples, nor of the maxillary 

 galea; careful dissection would be necessary in order to describe 

 the mouth-parts, which differ so completely from those of Ligyrus 

 as to suggest the propriety of a separate tribal group for Pseuda- 

 phonus, Aphonus and Orizabus, as previously suggested. The 

 legs and tarsi are nearly as in Ligyrus but rather longer and more 

 slender, the anterior tibiae always tridentate, similar in the sexes 

 and more obtuse at tip as in Aphonus, but they may be reduced by 

 wear to a pointed semi-edentate condition. The sterna are 

 are similarly pubescent, but the post-coxal process of the prosternum 

 is shorter, more slender, more acuminate and less pubescent, being 

 always in part nude, though never at the apex. Sexual differences 

 are exceedingly feeble and the male is relatively rare ; it differs from 

 the female only in its slightly shorter form, in having the last 

 ventral a little shorter, with its apex broadly and feebly sinuate 

 and the lower marginal beading of the pygidium less thick, the 

 pygidial apex more angulate, but the surface does not differ much 

 in convexity or sculpture. The base of the prothorax is immargi- 

 nate and strongly lobed medially throughout. The species are 

 rather numerous, disseminated over the southern Rocky Mountain 

 regions and far to the southward in Mexico, where at least one 

 species has been described by Mr. Bates under the name Cheiro- 

 platysfairmairei. Our species, so far as known to me, are as follows: 



Body distinctly pyriform, the elytra greatly exceeding the prothorax in 

 width. .2 



